Clinical Cases, Chairside Replacement of Class II restorations with hybrid-ceramic overlays 19 juli 2022 Case by CDT Daniele Rondoni When planning to replace Class II restorations, many things need to be considered. In order to select the most appropriate restorative technique and preparation design, it is essential to evaluate the amount and state of the remaining tooth structure, first. After repeated restoration replacement or in teeth originally restored with amalgam, for example, the remaining walls and cusps are often weakened and prone to fractures and cracks. When the cavity walls appear to be too thin or the structure is weak at the time of restoration replacement, it may be better to remove walls and cusps and opt for indirect adhesive restorations (overlays) instead of direct composite restorations. Due to favourable material properties – in particular a high flexural and compressive strength while being gentle to the opposing dentition and not too rigid for the surrounding tooth structures – we often opt adhesive restorations made of KATANA™ AVENCIA™ Block in those situations. The following clinical case is used to describe the replacement of two composite restorations with overlays made of the innovative hybrid ceramic material. Fig. 1. Initial clinical situation with composite restorations on the second premolar and first molar in need of replacement. The tooth structure particularly of the first molar was weak, with the distobuccal cusp already fractured. Fig. 2. Prepared tooth structure ... Fig. 3. Restorations milled from a KATANA™ AVENCIA™ Block after high-gloss polishing and characterization. Fig. 4. Finalized restorations on a resin model. Fig. 5. Adhesively cemented restorations in the patient’s mouth. FINAL SITUATION Fig. 6. Treatment outcome with a nice transition from the tooth structure to the restoration.